What is the weight of a steel rod 500mm diameter and 2.5 meters long?

To calculate the weight of a steel rod, you first need to find its volume and then multiply by the density of steel. The volume ( V ) of a cylinder is given by the formula ( V = \pi r^2 h ), where ( r ) is the radius and ( h ) is the height. For a steel rod with a diameter of 500 mm (radius of 250 mm or 0.25 m) and a length of 2.5 m, the volume is approximately ( V = \pi (0.25^2)(2.5) \approx 0.49 , \text{m}^3 ). Given that the density of steel is about 7850 kg/m³, the weight is approximately ( 0.49 \times 7850 \approx 3840 , \text{kg} ).